HOWTO see kernel command-line options used when you booted

Want to know exactly what command-line options were added to the kernel you have booted into? It's easy, the special file /proc/cmdline has the information. It is also available in the first few lines of dmesg. Thus; you can get the kernel options used to boot by either typing

Shell command(s):

cat /proc/cmdline

or

Shell command(s):

dmesg | head -n 10

These options are typically configured in the file /etc/sysconfig/grub as a GRUB_CMDLINE_LINUX= variable.